/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * QueryExecuteEvent.java
 * Copyright (C) 2005 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.gui.sql.event;

import weka.gui.sql.DbUtils;

import java.sql.ResultSet;
import java.util.EventObject;

/**
 * An event that is generated when a query is executed.
 * 
 * @see QueryExecuteListener
 * @author FracPete (fracpete at waikato dot ac dot nz)
 * @version $Revision: 7059 $
 */
public class QueryExecuteEvent extends EventObject {

	/** for serialization */
	private static final long serialVersionUID = -5556385019954730740L;

	/** the Db utils instance for the current DB connection */
	protected DbUtils m_DbUtils;

	/** the query that was executed */
	protected String m_Query;

	/** the produced ResultSet, if any */
	protected ResultSet m_ResultSet;

	/** a possible exception, if the query failed */
	protected Exception m_Exception;

	/** the maximum number of rows to retrieve */
	protected int m_MaxRows;

	/**
	 * constructs the event
	 * 
	 * @param source
	 *            the source that generated this event
	 * @param utils
	 *            the DbUtils instance that connected to the DB
	 * @param query
	 *            the query that is the basis for the resultset
	 * @param rows
	 *            the maximum number of rows to retrieve (0 for all)
	 * @param rs
	 *            the ResultSet that was produced (depending on the type of SQL
	 *            query it can also be NULL)
	 * @param ex
	 *            in case an exception occurred
	 */
	public QueryExecuteEvent(Object source, DbUtils utils, String query,
			int rows, ResultSet rs, Exception ex) {
		super(source);

		m_DbUtils = utils;
		m_Query = query;
		m_MaxRows = rows;
		m_ResultSet = rs;
		m_Exception = ex;
	}

	/**
	 * returns the DbUtils instance that was executed the query
	 */
	public DbUtils getDbUtils() {
		return m_DbUtils;
	}

	/**
	 * returns the query that was executed
	 */
	public String getQuery() {
		return m_Query;
	}

	/**
	 * returns the maximum number of rows to retrieve. 0 means all.
	 */
	public int getMaxRows() {
		return m_MaxRows;
	}

	/**
	 * is TRUE in case the exception is not NULL, i.e. the query failed
	 */
	public boolean failed() {
		return (m_Exception != null);
	}

	/**
	 * whether a ResultSet was produced, e.g. DDL commands like delete, drop or
	 * update do not produce one.
	 */
	public boolean hasResult() {
		return (m_ResultSet != null);
	}

	/**
	 * returns the resultset that was produced, can be null in case the query
	 * failed
	 */
	public ResultSet getResultSet() {
		return m_ResultSet;
	}

	/**
	 * returns the exception, if one happened, otherwise NULL
	 */
	public Exception getException() {
		return m_Exception;
	}

	/**
	 * returns the event in a string representation
	 * 
	 * @return the event in a string representation
	 */
	public String toString() {
		String result;

		result = super.toString();
		result = result.substring(0, result.length() - 1); // remove "]"
		result += ",query=" + getQuery() + ",maxrows=" + getMaxRows()
				+ ",failed=" + failed() + ",exception=" + getException() + "]";

		return result;
	}
}
